A study on visibility estimation of web-safe colors using paired comparison and discriminant analysis

This paper describes the visibility ordering of several web-safe colors, particularly in relation to age. The rapid dissemination of the World Wide Web has increased the importance of web page visibility research. The combination of foreground and background colors is an important factor in providing sufficient visibility, and the rating of color combination visibility should be considered when developing accessible websites. In this study, the visibility of several web-safe color combinations was examined using psychological methodology, that is, paired comparison. Visual stimuli were 18 chromatic and 3 achromatic web-safe colors. Twenty-eight subjects ranging in age from 21 to 75 were recruited, and all had normal color sensation. Subjects looked at two different colored characters simultaneously on a white background and were instructed to identify which they could see more clearly. To examine the relationship between psychological rankings of the color combinations and visual sensations, each color combination was first scored with regard to visibility by Thurstone's paired comparison technique. Second, visual sensation was deduced by applying Weber-Fechner's law to the luminance of the foreground colors. The results indicated that the luminance of a foreground color influenced visibility of web-safe colors; however, luminance alone was not sufficient to make a visibility rating. Chromaticity and chroma saturation are also necessary in the rating of chromatic web-safe color visibility.